The present invention pertains to a medical or diagnostic inspecting method. More particularly, the invention is directed to the method and apparatus for non-invasively obtaining measured information about metabolism using light beams of visible to infrared wavelength.
Today, clinical medicine has attained to the point where various kinds of diseases can be diagnosed on measuring results about morphology of body organs. And, imaging systems for diagnosis use such as a supersonic diagnostic system and an X-ray CT scanner have been so progressive that they can detect morphologic abnormality entailed by diseases with considerable accuracy. In general, metabolic functions are diagnosed in vitro assay, though a positron CT scanner or MRI system provides a certain kind of metabolic function.
U.S. Pat. No. 4,281,645 on the other hand, describes a method and an apparatus for optically monitoring metabolism in body organs in vivo depending upon the fact that a certain kind of metabolic material contains specific optical absorption bands. The Japanese First Patent Publication No. 60-72542 (1985) describes a system for obtaining a tomogram, which indicates how metabolic materials are distributed in body organs. The system is designed to match each element included in the system for metabolic modeling to each element included in an X-ray CT scanner.
The Japanese First Patent Publication No. 63-115548 (1988) has proposed a method for eliminating a light-scattering phenomenon in the foregoing optical inspecting system. The scattered light mentioned in the art, however, means the light scattered by the materials external of the body, that is, "stray light" and the light reflected on the surface of a body to be inspected. Further, the Japanese First Patent Publication No. 63-206655 (1988) discloses a method of comprising the steps of dividing a light pulse into two, allowing one pulse to pass through a human body to be measured, introducing two pulses into crystals, the one as a sampling light and the other as a reference light, detecting second higher harmonics generated from the crystals, inhibiting detection of light scattered in the human body by referring the second higher harmonics, and detecting only the light transmitted through an optical path with a predetermined width.